One of the goals of the natural sciences– for example biology– is to provide new
information about certain phenomena with previously unknown nature. Their contribution
to our knowledge is substantial. From this perspective, logic is seemingly
not substantial. Sometimes, logic’s insubstantiality is taken for granted while explaining
the alleged insubstantiality of other notions. For example, according to
truth deflationism, truth is a non-substantial notion in the sense of being a logical
property. However, it is not fully clear to what such an insubstantiality amounts.
It is also debatable whether logic really is insubstantial. In this paper, we aim to
clarify this issue by proposing a formal way of looking at it. In particular, we used
the notion of conservativity, which has already been used by truth deflationism, for
a similar aim. We show that if insubstantiality is read in terms of conservativity,
then classical logic is substantial. We then argue that such a verdict of substantiality
can be resisted if precise stances on certain prima facie unrelated issues of philosophy
of logic are taken, or an anti-exceptionalist view is adopted.
